1. Field of the Invention
The present invention relates to a proportional magnetic valve for generation of a pressure proportional to applied current, with an axis, which is connected with an armature, which is surrounded by at least one coil, which during current flow therewith in connection with the armature produces a magnetic force, which is directed counter to a closure force effective upon the axis.
2. Description of the Prior Art
With such magnetic valves, hydraulic medium is supplied through a pressure pipe of a working line or conduit. The pressure building-up here is dependent thereon with which closure force the axis of the magnetic valve is held in a closure position, in which the magnetic valve closes-off a tank return line for the hydraulic medium. If the pressure in the working line or conduit exceeds the closure force produced by a pressure spring, the axis is pushed back against this closure force, so that the hydraulic medium can come into the tank return line. In order now to be able to adjust or set different working pressures, the coil has current flow fed thereto whereby a magnetic force results directed counter to the closure force effective upon the axis. Thereby the axis is pushed back already with small or nominal working pressures. With the production or manufacture of such magnetic valves, a problem arises whereby as a consequence of tolerances with the same or identical current values there cannot be set or adjusted the same or identical working pressures.
For this reason, the individual parts of the magnetic valve during manufacture or production must be produced in various narrow, tight or close tolerances, which makes the manufacture or production of such a magnetic valve more expensive.